A prior keypad used in a portable terminal is fabricated by attaching a keypad rubber, which is fabricated through a separate process, to keys printed with characters or numbers made through a key molding process by using adhesives. The keypad fabricated as above is assembled by being fixed on a printed circuit board where an LED (Light Emitting Diode) for a backlight is attached.
In the prior keypad used in the portable terminal, when a key is pressed, the keypad generates a signal by contacting a dome switch located on the printed circuit board with the key, and when released, the key returns to an original position. In the prior keypad, characters printed on the keypad rubber are recognized when the LED emits light with point luminous properties.
However, the prior keypad adopting the LED for a backlight causes non-uniformity of brightness. For instance, a part of the keypad near to the LED looks bright and a part far away from the LED looks dark owing to the point luminous properties, thereby deteriorating visibility.
In addition, since in the prior keypad applied with EL devices, keys adhere to the keypad rubber that is made through another process by using the adhesives, the keys' click sensitivity is deteriorated and flexibility is reduced as well. Thus, in case a key is pressed, it causes a problem of a wrong operation that another keys adjacent to the pressed key are simultaneously operated.